An automatic transfer switch is a switch that can transfer a power source from a first source to a second source when a disturbance is sensed in a power transmission. A conventional automatic transfer switch includes coupling the primary power source and a backup power source to the transfer switch to provide temporary power to the load if the primary source fails. A conventional automatic transfer switch can include a bypass isolation open or closed transition system that switches between a load and two sources of power.
In conventional approaches, some facilities may have power systems structured to provide an uninterruptable power supply. The primary source may be the power utility and the backup source may be a backup power source. Power can be supplied over a period of time from both sources. During maintenance of a conventional automatic transfer switch the entire facility must be taken off line or the facility may have power supplied from one source but removing the backup capabilities of the system.